Metal wheel



April 20, 1948. c. EKSERGIAN 2,439,848

METAL WHEEL Filed June 21, 1943A 2 sheets-sheet 1 A TTORNE Y April 20, 1948. c. L. EKSERGIAN METAL WHEEL Filed June 2l, 1945 2 Sheets-Sheet? IPIC@ NVENTOR Carolus Llkserq icm B UAIORNEY Y I I i Patented Apr. 20, 1948 UNITED STATES PATE-NT OFFICE METAL WHEELVV Application June 21, 1943, Serial'No. 491,699

(Cl. 74A-2303)' 3 Claims'. 1.

This invention' relates to ametal wheel; and has as* an object' theIk provision otV a'- wheel of this typehaving radial rigidityand limited axial flexibility; Thefvwheel' of the' invention is claimedin this application, whereas thepreferre'd apparatus byy whichl itl is manufactured is claimed in the patent to- Harold Strickland; Jr.,. 2;402,509, granted June-18', 1946i A feature of theinvention consists in provision of aA Wheel having a hardenedv intermediate zone which may'best be produced by' the induction heating machine claimed in saidz patent and' also= descr-ibedL hereinafter.v

In the v heat treatment of metall products byvinlductivel` methods, it is frequently desirableto limitthe extent of heat application to predetermined areas. In thecaseofA wheels, for example, it may bei desirable to heat treat the periphery thereof without disturbing theV web-orinterior support'- ing= structure;

Among the features-of the present invention is the provisionof4 awheelY having,` an anniilar edge area rendered relativelyy hard andI rigidwithout internalVZV modification: of! the f interior supporting web. 'Ihis maybemadeby use of'inductive heating means that maybe applied to-a circular object in an annularl areaintermediatetheedge and center. In this operation heatv treatment is effected onan integral metal wheel I structure without producing axial distortion of the-- metal. Eff- .fect-ive quenching means is provided'without disturbing the requisiteproximityl of treated area and heat producing coils;

AnI arrangement of apparatus andy a specific form of-l preferred product arev described in the following specification andI shown in the accompanying drawings, in which Fig. 1 is aside elevation in part section of the heating apparatus including also a section ofr a wheel-inserted for treatment;

Fig; 2V is a plan viewl of the apparatus with thewheel and wheel lock removed;

Fig. 3- is a detail section showing inand outleads-forelectrical and cooling media;

Fig. 3 is a 'detail section showing a coil sup- POI'TI; and

Fig. 5 is a detail showing a modified quenchlng apparatus.

Referring particularly to Figures 1 and 2, there is` disclosed' an inductive heating apparatus intended primarily for the heat treatment of circular bodies or articles4` such as wheels, rims andthelke. On the base plate I0` is mounted by supports III' the angegenerally indicated by the numeral I2. The base plate I0 is in the general shape of a flattened disc and is hollow in sections to form a reservoir I5 for the quenching fiuid- I3, the inlet pipe connection to the reservoir of the base plate being at I4. There is attached at the base periphery the upwardly extending front and side ilange I6 forming with the back plate I1 a pan shaped receptacle for quenchfluid after egress from the quenching nozzles. The back plate- Il is adapted to extend above the heating apparatus and forms a support for the transformer (not shown); lead inv bus bars and other auxiliaryV equipment forming a part of the complete heating apparatus assembly. The flange IB is attached to the base section ofthe baseplate bymeansofbolts I8.

The-central section of lthe base plate I2A is aperturedand extended on the upper side inv a tubular support member I9 internally threaded at its upper end. Positioned within the tubular member I9 is awork support generally indicated by the numeral 2i)a This support includes a stub shaft 2| positionedfwithin the tubular member i9and supported'y therein by means of ball bearing units at the upper .and lower ends of the tubular support I9.- Tovprovide for the ball bearing connection asimentioned, the support I9 at its upper end isfor-med with annular recesses 22 and 23, the recess 22 being adapted to receive -a ring shaped bearing 24 having ball bearing runways formed therein and adapted inV conjunction with a smaller ring 25 fixed on shaft 2i, having outwardlyvformed runways therein to hold ball bear ings` 26- in operative relationship. The ring 25 is mountedl on a section ofthe stub shaft 21| of reduced diameter, the edge formed by this section supporting the ring 25 in position Immediately abovethe ring 22, in screw threaded engagement with the end surface of the tube I9 is a nut 2lwhich is adapted to hold the ring 22 in fixedposition upon the end of the tube I9.

The lower end of the stub shaft section 2| is supportedv with reference to the base plate I0 by means of the ball bearing unit including the runways rings 6Iv and 62 and ball bearings 63. The ring 6I is fastened directly to the shaft 2|l andthe ring 62 is secured in position by the locking wire 64. The stub shaft 2l is apertured on its lower end to receive an operating shaft 65.

Fixed to the shaft 2l directly above the inner ringv 25 is-a circular work support plate 30 having an annular edge extension beyond the external boundary of the supporting tube I9, Skirt 3i is fastened to the under side of the plate 3U, the same enclosing the support I9 and extending downwardly to a zonel adjacent the base plate I0'.

3 Directly above plate 30 is positioned the work centering head 30a, the same being in the shape of a short cylinder provided with bayonet slots 32 on the periphery thereof. This head is held in position on the shaft by means Oof the terminal nut 34 which is screw threaded to the end of the shaft 2l and holds the head and various other funits securely on the shaft end; A Washer 33 separates the nut 34 from the head 3|.

Means are provided for clamping the work piece in position on the work centering head 33a in the work clamping member 4B, the latter comprises a ring 4l provided with pins 42 adapted toV move into, and be secured by the bayonet slots are also directly connected to the brackets 16 from which bus bar connection is made to the transformer. These brackets are also provided with ducts 11 which communicate with the terminals as shown in Figure 1.

Quenching means for the heating apparatus is provided by a plurality of annularly displaced standpipes 80 which at their bases communicate with the reservoir I3 in the base platell in the area intermediate the stub shaft 2| and the 'standards 18. The outlet ends of these stand pipes 80 terminate adjacent the inner edge of the inductor coil 61 and adjacent these ends the pipes are' provided with outwardly positioned spray ,nozzles of such shape as to throw under pressure a fan-shaped stream of fluid against the rotating surface section 51 of the wheel. Obviously, when the drawing and which is adapted for heat treatment by the described apparatus is a sheet metal wheel 50, commonly referred to in the trade as a bogie wheel, a primary purpose of which is to serve as a guide wheel for heavy traction Vand automotive apparatus such as tanks and which is consequently subjected to severe treatment in use. Ordinarily these wheels undergo heavy radial axial or lateral stresses so that not only must the bearing rim of the wheel be suiiiciently hard to resist road impacts and nicking, but also the web or body of the wheel must possess sucient elasticity or resiliency to permit lateral yielding when the Wheel is subjected to severe lateral stresses. As illustrated this Wheel consists of a single metal disc, the same having a flattened hub section, a peripheral road bearing section having hardened metal areas and an intermediate sigmoid section joining the hub and edge sections. Preferably the hub section 5| is formed with apertures annularly displaced adapted to receive the heads of studs 52, the latter being threaded into apertured extensions 54 formed about the edge of the support plate'S. These studs serve as direct supporting means for the wheel upon the plat-e 30. The sigmoid section 55 includes two reversely curved annular segments connected by a flattened/area, the same being approximately S-shaped. yThe-edge section 56 is approximately V-shaped with the V opening toward the` hub of the wheel. One segment of the V, 51, joins the sigmoid and is inclined angularly relative to the radial hub section. The other segment 55 of the edge section also is inclined relative to the hub section, forming a reversely turned rim for the Wheel. As described to this point, it is apparent thatthe wheel may be mounted upon the rotatable stub shaft 2| upon which it is radially secured by means of the support plate 30, the centering head 30a and the clamping member 40. Y

Heat means 66 for the work piece is provided in a single turn inductor 51 which is supported from the base plate I0 by standards 18 connected through insulation 85 to the inductor lugs 86 in the shape of a hollow tube adapted to receive and transmit the cooling fluid 68. One face 69 of the inductor tube is flattened and angularly positioned with reference to the base plate Ill so as to lie in acute angular relationship to the edge section of the heating coil. The ends of the single coil 61 are led outwardly as shown particularly in Figure 3 to form terminals 10 and 1I. These terminals contain ducts 12 and 13 which have connection to the communicating inlet and outlet ducts 14 and 15 for supplying a coolant to the inductor coil. These terminals the wheel is rotating at a high speed, there is added to the normally radial outward pressure acting on the fluid, a centrifugal force due to the wheel rotation, so that the tendency to forcethe fluid by the adjacent wheel surface is pronounced.

In the operation of the heat treatment apparatus the workpiece such as the wheel illustrated is placed in position and rotative power applied. Alternating currents are then led into the inductor circuit, which may be of a frequency inthe order of 3000 cycles. The inductive action of the current in the inductor coil 61 heats the adjacent surfacer51 of the wheel to a temperature above the critical point for the metal at which temperature it is preferably held a short time period such as five seconds depending on the characteristics of the steel; after which Withthe wheel still rotating the quenching uid is applied. As previously mentioned the normal pressure of the fluid combined with the centrifugal rotative action ofthe wheel causes rapid cutow of fluid which is normally of sufficient force to prevent the formation of steam pockets. This rapid flow of cooling fluid rapidly reduces the metal Itemperature,a time period of six seconds being usual for a wheel as described, and imparts to the metal section 51 a desired degree of hardness.. It is noted that the control over the degree of hardness may be secured either by control of the force of the quenching nozzles or by the degree of maintenance of the current in the inductor coil during the initial quenching operation. It is pointed out that the speed of heat application to wheel surface 51 is such that only a limited depth of` material is heated. Accordingly, a steep` temperature gradient is formed between surface, 57; andthe back surface, and on cooling advantage is derived from the relatively-cool backing as an auxiliary quenching medium to accomplish rapid cooling of the surface 51. s A

A wheel made according to the described process possesses adequate edge hardness forfresistance to impact and at the same time yields in the web so as to absorb radial and axial shock stresses. As appears from the process, the intermediate annulus 51 is the wheel area of greatest hardness. The annuli and 58 bounding the annulus 5l are of lesser hardness and greater flexibility since these areas are out of the direct path of the quench stream. It is pointed out-that the wheel is readily and firmly placed into and out of position; that the rotatable mountinsures a uniformity in both heat and quench; and that through the hydraulic head as Well as the centrifugal force of rotationrthe spray quench is forced quickly past the juxtaposed surfaces inpockets.

Figure 5 illustrates a modiiied form of quenching apparatus nozzle and inductor heating surface. In this modification instead of a slit nozzle stand pipe 89 a tubular nozzle 92 projects outwardly at an angle in direct line with the plane of the section 51 of the wheel to be heated, the nozzle terminating approximately at the inner edge of the inductor coil 9i. The pipe surface of the coil 9E instead of being formed with a straight-section iiuid surface includes a curved section 93 forming an offset between a lower straight section 99 and a higher straight section 95, the inclination of the straight surface 95 being approximately the same and the curvature of the section 93 of the inductor being approximately thev same as the adjacent edge secticn of the wheel. With this arrangement it is pos-- sible to force the quench iiuid between inductcr and Wheel surface with greater velocity and to extend the hardened area of the wheel to a point nearer an'extreme outer edge of the same.

While the term wheel is used with reference to the specific showing of the drawing, it is understood that in the claims the meaning is broadened to include any disc-like article subject te similar methods of heat treatment.

The term web as used in the claims is intended to describe the wheel area between the rim annulus 57 and the hub aperture.

Modications of the invention other than that shown may of course be made and no limitation therefore is intended in the described embodiments other than that which is required by the asas and an edge section outwardly joining said sigrnoid section, said edge section including a rigid strip annulus adjoining said sigmoid section and a re-entrant annulus adjoining said rigid annulus, the re-entrant annulus and sigmoid section being iiexible relative to said rigid annulus.

2. A wheel comprising a hub section, an edge section, and a sigrnoid section between the hub and edge sections, said edge section including two annulus segments edge-joined at the wheel periphery, one of said segments having a free edge displaced inwardly from the periphery toward the wheel axis, said edge segment being softer than the joined segment.

3, wheel formed of a single sheet of metal, said sheet having three concentric annuli, the edge and intermediate annuli forming the peripheral wheel rim surface and the intermediate annulus having greater hardness and less resiliency than the other annuli.

CAROLUS L. EKSERGIAN.

REFERENCES CE'ILED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 691,929 Bicalky Jan. 28, 1902 1,439,460 Williams Dec. 19, 1922 1,527,418 Laughlin Feb. 24, 1925 1,604,596 Odenkirk Oct. 26, 1926 1,794,445 Davis Mar. 3, 1931 1,811,203 Laughlin June 23, 1931 2,268,839 Lyon Jan. 6, 1942 2,295,531

Heaslet Sept. 15, 1942 

